Which Diesels For Re-power?

k9th · Post by **k9th** » Mon Jul 18, 2011 8:07 pm

In keeping with our plan to completely bring SeaDog back to her original condition, next spring is the time I had planned to do the re-power. I am leaning heavily toward going with diesel engines instead of gas but know very little about marine diesels. My only exposure to diesels at all was my Ford F-350 diesel dualy pick truck which I loved.

What is the best diesel to go with and why? I know there may be several opinions on this and that's what I want - some honest input from those who have used them. I will be having them installed by my mechanic so making it an easy install for me personally is not necessary. But obviously I want it to be as easy and seamless as possible. I currently have twin Merc 255s with Velvet Drives and purchased new fuel tanks a year ago this past spring.

Any and all input will be appreciated. I am addressing this now because I want to get the decision made and the engines and all other accessories purchased late this fall and winter so they will be ready to drop in next spring.

prowlersfish · Post by **prowlersfish** » Mon Jul 18, 2011 9:16 pm

Of course My first choice would be cummins B series 270 or 330 If you have room ( tight fit on mine). You can get a deal on the 330 remans . My second choice would be Yanmar . ( around 300 hp) . The yanmar is more compact and would be a easier fit ( easy means less labor $$$ ) Volvo also has some good engines These are the only Real choices That come to mind.

There are other choice out there like the Cummins/mercruser 4.2 L and the 6.5 GM But they are not in the same league as the B or Yanmar . You won't service or life from them like the B or yanmar or Volvo.

re powering to diesels is a costly long term commitment saving a few bucks on the cost of the engine now could cost you a lot in the long run .

Plan on 60-80K or more installed going new or factory reman

jav · Post by **jav** » Mon Jul 18, 2011 9:35 pm

you asked for opinions so here goes.

unless you absolutely love your boat, converting it to diesels by paying a professional mechanic to do it will make no financial sense. It would very likely be significantly cheaper and easier to sell it and buy a boat that has diesels already. If you're OK with that, then I agree with Paul.

Factory Cummins remans (non-electronic) are about as economical as you can you can get on a known commodity. They make a great engine, very heavy duty- they are a little larger because of this but if you can fit them.... they would be my first choice.

Yanmar and Volvo would probably fit better and provide lighter weight/per HP and perhaps a little better economy BUT- they will be way more expensive to buy and service.

If you go used running take-outs, the choices are less clear and obviously there would be some risks.

If your using a mechanic, I would recommend finding a reputable professional you trust and listening to his advice. You'll need support so what they are comfortable and familiar with is an important consideration.

Good luck.

Tri-Guy · Post by **Tri-Guy** » Mon Jul 18, 2011 10:21 pm

Tim I looked into the same thing,in the end wayyyy to much money.I also want to moderize my Tri cabin,I havr done tons of work on the boat.The best option I have come up with is brand new fuel injected crusader 5.7 small blocks.This package allows you the auto sync to run both engines on one stick while underway,nice not to play around with both sticks.I have played around with the numbers many times,total price with install should be less than 30k.I know they are not close to youbut,marine engines in Holliston Ma. is by far the best price for the entire package 1800 rus new is the number.P.S I am not part of this company,but I have bought lots of stuff from them.Maybe next I will buy this package and let you know how it worked out. John M

k9th · Post by **k9th** » Tue Jul 19, 2011 5:48 am

Thanks for all of the very detailed responses and advice.

Yes, jav, we really love the boat and have committed to doing a complete job on her. She may very well be my "last" boat given my age and how well we like the boat.

I guess I wasn't expecting quite that much of an investment, so thanks for all of the information. I may have to move it back another year to get the additional funds needed or consider re-powering with gas engines.

It sounds like the Cummins or the Yanmar would be the way to go. Paul I know you have an F-36 so I am assuming your engine room is very similar if not identical in size to mine.

I don't have the knowledge or physical ability to do the work myself and have a very reliable and trusted mechanic who has a family business that has been loving and working on boats for years - I trust him implicitly to do a good job and make sure it is done right.

jimbo36 · Post by **jimbo36** » Wed Jul 20, 2011 4:27 pm

Tim, I have given consideration to repower with diesels in my F36 Tri cabin. Yanmar would be my choice following my reserch. While it is true I could buy a lot of boat already equipped with diesels for what the project will cost but if I traded boats I will be looking at used engines. Should I need to rebuild one I would be out what I may have saved.

Part of my reasoning to go with diesels is reliability.

I want to do the Great Loop in a few years from now. jimbo36

Mike Kulp · Post by **Mike Kulp** » Wed Jul 20, 2011 5:20 pm

I would love to put diesels in my 10 meter mostly for fuel economy. My wife and I were running about 100 hours a season 5 years ago ( Slowed Down some ) And I did the math and priced out 300 hp yanmars with 7 degree down transmissions, they were $22,500 per motor. After doing the math there was no way I could justify the engine swaps and generator. I can buy a lot of gas for that kind of money. I still have not given up on the idea I keep my eyes open for some used B series cummins that I can rebuild at my shop and install myself. There is a farmer up here in Lancaster Pa. that buys every used diesel he can find mostly Detroit, Cats, Duetz, John Deeres but some cummins, He has fields of them in rows like growing crops but I have not found complete marine engines with transmissions yet. of course I would like to buy them cheap so I could justify the cost to my wife because I can only lie about the price for so long until she sees the bills come through the shop. So I keep dreaming about it and you can not beat the sound of a cummins.

RWS · Post by **RWS** » Wed Jul 20, 2011 5:22 pm

SAFETY

RELIABILITY

EFFICIENCY

INCREASED RESALE VALUE

INCREASED RANGE

INCREASED BEST ECONOMICAL CRUISE SPEED (SIX KTS FOR US)

That said, if your gas engines are fine, it makes little sense.

If they're close to done, the NEW issue has value, not just with regard to warranty, but more importantly to service history.

Little things like oil changes, zincs and coolant changes can have a huge effect on cvostly repairs or lack thereof in year 8 or 12.

I do love my Yanmars !

That 10 Meter is now quite the boat. Totally different ride.

Once you go over to the diesel side, you won't come back.

RWS

prowlersfish · Post by **prowlersfish** » Wed Jul 20, 2011 9:34 pm

Yes once you go diesel you won't go back

Once you have gone diesel you will understand.